Steam engine valve gear



Sept. 24, 1935. w. w. DooLEY STEAM ENGINE VALVE GEAR Filed July 9, .1934 3 Sheets-Sheet 1 m, .m K .MM QM L. \v ang Z .mf W K Sept 24, 1935- y W. w. DooLEY 2,015,380

STEAM ENGINE VALVE GEAR Filed July 9, 1934 3 Sheets-Sheet 2 Inventor nazi@ WIW/5,

wd Y q flllomey sept.f24,1935. W, w DOOLEY L zmsso STEAM ENGINE VALVE GEAR Filed July 9, 1934 3 Sheets-Sheet 3 Inventor naz/@f 14K/7M@ tlomey Patented Sept 24, 1935 1 Claim.

This invention appertains to new and useful improvements in means for controlling the reciprocatory motion of the steam induction and exhaust valve for all types of reciprocatory steam engines.

An important object of the present invention is to provide a control for varying the valve lead at the will of the operator by shifting the control point of the conventional lap and lead lever along the axis of the said lever, thereby shortening the distance through which the control point will move horizontally. i

Another important object of the present invention is to provide means for varying thecutoi with modications of the lead by changing the position of the radius rod center with respect 'to the lap and lead lever through the movement of the actuated end of the radius rod in a developed arc.

Still another important object of the present invention is to provide a link structure whereby the actuated end of the radius rod is driven.

A further object of the invention is to provide a worm and gear vdrive for the eccentric with means for reversing the motion of the worm to acquire a reversing action of the engine independently of the lap and lead adjusting means.

Other important objects and advantages of the invention will become apparent to the reader of the following specification.

In the drawings:

Figure 1 is a side elevational view partly in section showing the mechanism at one side of a locomotive.

Figure 2 is a fragmentary top plan view of the eccentric drive.

Figure 3 is an enlarged vertical sectional view taken substantially on line i-3 of Figure 2.

Figure 4 is a side elevational view of the worm shown in Figure 3.

Figure 5 is an end elevational view of the worm shown in Figure 4,

Figure 6 is a side elevational view of the yoke for the worm.

Figure 7 is an end elevational view of the yoke.

Figure 8 is a side elevational view partly in section showing the squared shaft for the Worm Referring to the drawings wherein like numerals designate like parts, it can be seen that a description of the gear at one side oi the locomotive will suffice as it is to be understood that the construction of each side oi the locomotive is identical, with the exception of the worm drive which will be described subsequently.

In the drawings wherein like numerals designate like parts, it can be seen that numeral 5 represents the drive cylinder in which the piston 6 is located while numeral l represents the slide valve for distributing steam to the cylinder 5. From the piston 6 extends the pitman B which connects to the usual main cross head il. An arm il! extends from this crosshead 9 and to this is pivotally connected the usual lap and lead lever ll which is pivotally connected as at l2 to the stem i3 of the distributing valve l. Numeral ill represents a crosshead pivotally supporting one end of the radius rod i4 which is provided with a laterally disposed pin I5 operating in the longitudinally and axially disposed slot l@ in the lap and lead lever I l.

An oscillating link Il is clearly shown in Figures 9 and 10 and consists of Aa rectangular frame-like bar i8 having longitudinally extending slots iS-IQ in the side portions a-a, these slots I9 being on a definite curve predetermined to properly shift the rod lli. It will be observed that the upper portion of this frame lil is provided with laterally disposed trunnions 2GB-2@ journaled through portions b-lJ of the locomotive frame 2| and that the radius rod lll extends rearwardly through the frame or bar i8, that is between the side portions a-a to connect by the pivotal link 22 to the bell crank 23, the latter in turn being controlled by a remotely actuated rod 24. The radius rod lil' at the oscillatory link ll is pro-vided with laterally disposed trunnions 25 which ride in the slots lll-i9. The lower portion of the bar l (see Figure l0) is provided with a transversely extending bore 26 to accommodate a pivot pin 2'! whereby one end of the pitman 28 is pivotally connected to this link bar while the opposite end is eccentrically and pivotally connected to the eccentric wheel 2li. lt will be observed that all of these details are duplicated on the other side of the locomotive and that the two eccentric wheels 29 are located on a common shaft 3U, which, as shown in Figure 2, is provided with a beveled gear 3l with which meshes the beveled pinion 32. The beveled pinion 32 is carried by a short shaft 33 which is connected to the extension 34 of the squared shaft 35 by a slit or splined connection 36.

The shaft 31 of the drive Wheels 38--38 is, as shown in Figure 3, provided with a gear 39 which meshes With the slide Worm 40 on the squared shaft 35. The squared shaft 35 is free to rotate in the bearing mount 36', While the Worm 40 is free to slide on this shaft and this sliding action can be effected by the rod 4I. It is preferable that this rod be actuated by a compressed air cylinder piston and, as is shown, the rod connects to an ear 42 at the top of the U-shaped harness or yoke 43 Which is provided with a fork 44 at each end thereof for engaging With a reduced portion 45 at the corresponding end of the worm.

It can now be seen that the valve lead can be adjusted at the will of the operator by actuating the rod 24 and through the link I1 shifting the control point at l5 (see Figure 1) up or down along the axis of the lap and lead lever l I, thereby shortening the distance that the control point Will move horizontally.

It will be observed that the Worm gear 40 serves I to drive the eccentric Wheel 29 and consequently the valve 1 in their definite adjusted positions. In order to reverse the motion of the engine independently of the lap and lead adjustment rod 24, the worm gear 40 is simply shifted horizontally While in mesh With the driving gear 39. By this horizontal movement the worm gear is rotated in a direction counter to that of the previbus motion, thus revolving the eccentric Wheels 29 through an arc proportional to the horizontal movement of the driven Worm. Through the connecting link or pitman 28 to the oscillatory link l1 controlling the movement of the reciprocating valve With varying lap and lead, the diS- tance of the valve travelled in the reverse direction is made proportional to the horizontal distance the driven Worm is moved, thus placing the valve in a position for steam admission to the opposite end of the steam engine piston 6 and thereby reversing the motion of the engine in the direction of the driven crank. This change in valve travel can be accomplished for any position of the main engine crank or at any point in the valve or piston stroke, being a simple, positive, eflicient and effective means for reversing the engine through a change in the relative positions of the main engine driving crank pins and the connection on the pitman 28 with the eccentric wheels 29.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size, and materials may be resorted to Without departing from the spirit and scope of the invention as claimed hereinafter.

What is claimed is:

Reversing mechanism for distributing Valves of steam engines comprising a drive Wheel operative gear, a slidable control rod, a Worm having a polygonal opening therethrough, a rotatable shaft having a polygonal cross sectional portion for disposition through said Worm along which the worm is slidable, a yoke carried by the control rod and engaged with the Worm, said slidable control rod being operative to shift said Worm on the shaft, and actuating means responsive to the rotation of the shaft for regulating a distributing Valve with which it is connected.

WALTER W. DOOLEY. 

